9500 startup problems... Now that isn't a surprise.
1. Check the PRAM battery voltage. While it's out, unplug the mains power cable, leave the Mac to rest for 20 minutes, and then hold down the CUDA for a minute. Reassemble the Mac with a reliable PRAM battery, and try again. If that fails, repeat the above, leaving the Mac without a PRAM battery overnight.
2. Check out 9500 pain at http://www.xlr8yourmac.com/. Moving cards, adding cards, changing CPU, changing RAM is always a headache. The 9500 is possibly the worst of the PCI PowerMac family, owing to case inaccessibility.
3. Check whether it is a SCSI problem by unplugging the cables from the logic board. You should be able to boot from floppy without SCSI devices present.
1. Check the PRAM battery voltage. While it's out, unplug the mains power cable, leave the Mac to rest for 20 minutes, and then hold down the CUDA for a minute. Reassemble the Mac with a reliable PRAM battery, and try again. If that fails, repeat the above, leaving the Mac without a PRAM battery overnight.
2. Check out 9500 pain at http://www.xlr8yourmac.com/. Moving cards, adding cards, changing CPU, changing RAM is always a headache. The 9500 is possibly the worst of the PCI PowerMac family, owing to case inaccessibility.
3. Check whether it is a SCSI problem by unplugging the cables from the logic board. You should be able to boot from floppy without SCSI devices present.